Almost everyone making online transactions thinks that using bitcoins would be a good way to stay anonymous. But the truth is bitcoin transactions are not really anonymous at all. All transactions are recorded and can be seen publicly through the blockchain. When you use your bitcoin to pay for goods and services online, you will need to provide some private information in some cases. This means that your transactions can be traced by a third party to find information. In order to avoid this from happening, bitcoin mixers provide services where your bitcoins are mixed with others to make it harder to be traced back from the original owner.
Do you think that it is a must for everyone to use a bitcoin mixer? Why and for what purposes?
I think it should be done by everyone. Because your data are private and belong to you and to you only.
It's a measure of security to your data and a great deal for your privacy, so what's against it? It's fairly simple to mix coins, so go for it!